Installation of the Air-Conditioning Distribution Ducts

TASK 21-20-00-410-001-A
Installation of the Air-Conditioning Distribution Ducts

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	2	ACCESS PLATFORM 2M (6 FT)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.05RAJ9)	Adhesive Film Tape-- Film PTFE -
(Material No.05TGA1)	Adhesive Tape-Insulation Blanket - -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
811, 824, 825, 826

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-33-21-618-001-A	Pre-conditioning through the LP Ground Connection (Aircraft Electrical Power Available)
TASK 12-33-21-618-001-A-01	Pre-conditioning through the HP Ground Connection
TASK 12-33-21-618-001-A-02	Pre-conditioning with the APU
TASK 12-33-21-618-001-A-03	Pre-conditioning through the LP Ground Connection (Aircraft Electrical Power Not Available)
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 25-13-41-000-001-A	Removal of the Ceiling Panels
TASK 25-13-41-400-001-A	Installation of the Ceiling Panels
TASK 25-23-42-000-001-A	Removal of the Ceiling Panels - Forward Utility Area
TASK 25-23-42-400-001-A	Installation of the Ceiling Panels - Forward Utility Area
TASK 25-23-43-000-001-A	Removal of the Upper Sidewall Panel
TASK 25-23-43-400-001-A	Installation of the Upper Sidewall Panel
TASK 25-23-44-000-001-A	Removal of the Lower Sidewall Panels (Dado Panels)
TASK 25-23-44-400-001-A	Installation of the Lower Sidewall Panels (Dado Panels)
TASK 25-41-41-000-001-A	Removal of Lavatory A
TASK 25-41-41-000-001-B	Removal of Lavatory A
TASK 25-41-41-400-001-A	Installation of Lavatory A
TASK 25-41-41-400-001-B	Installation of Lavatory A
TASK 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 25-54-12-000-002-A	Removal of the Ceiling Panels in the Forward Cargo Compartment
TASK 25-54-12-000-003-A	Removal of the Sidewall Panels in the Forward Cargo Compartment
TASK 25-54-12-400-001-A	Installation of the Forward Cargo-Compartment Partition
TASK 25-54-12-400-002-A	Installation of the Ceiling Panels in the Forward Cargo Compartment
TASK 25-54-12-400-003-A	Installation of the Sidewall Panels in the Forward Cargo Compartment
TASK 25-55-11-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR47
TASK 25-55-11-000-002-A	Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-11-400-001-A	Installation of the Aft Cargo-Compartment Partition at FR47
TASK 25-55-11-400-002-A	Installation of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-12-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR65
TASK 25-55-12-000-002-A	Removal of the Ceiling Panels in the Aft Cargo Compartment at FR59/FR65
TASK 25-55-12-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 25-55-12-400-001-A	Installation of the Aft Cargo-Compartment Partition at FR65
TASK 25-55-12-400-002-A	Installation of the Ceiling Panels in the Aft Cargo Compartment at FR59/FR65
TASK 25-55-12-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access
TASK 53-00-00-000-801-A	Removal of the Floor Panels in the Cabin from FR12 to FR70
TASK 53-00-00-000-801-A-01	Removal of the Floor Panels in the Cabin from FR12 to FR70 (Alternative Removal Procedure - Dry Sealing Concept)
TASK 53-00-00-000-801-A-02	Removal of the Cabin Floor Panels from FR12 to FR70 (Alternative Removal Procedure with the Skyflex Option)
TASK 53-00-00-400-801-A	Installation of the Floor Panels in the Cabin from FR12 to FR70
TASK 53-00-00-400-801-A-01	Installation of the Floor Panels in the Cabin from FR12 to FR70 (Alternative Installation Procedure - Dry Sealing Concept)
TASK 53-00-00-400-801-A-02	Installation of the Cabin Floor Panels from FR12 to FR70 (Alternative Installation Procedure with the Skyflex Option)
TASK 53-12-13-400-001-A	Installation of the avionics compartment floor panels
Distribution Ducts Location
Examples of Distribution Duct Connections
Examples of Distribution Duct Attachment Methods

3. Job Set-up
Subtask 21-20-00-860-050-A

A. Aircraft Maintenance Configuration
(1) Make sure that:
(a) The aircraft electrical circuits are energized (Ref. AMM TASK 24-41-00-861-002).
(b) On the panel 30VU:
1 The APU BLEED pushbutton switch is in the off position (the ON legend is off).
2 The ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on).
3 The warning notice to tell persons not to operate these pushbutton switches is in position.
(c) On the HP and the LP ground connector the warning notice to tell persons not to supply the ground air is in position.
(d) For the cockpit area supply and ventilation ducts:

the access panels are removed as necessary (Ref. AMM TASK 25-13-41-000-001).

(e) For the cockpit riser duct on the LH side at FR13:

the lavatory is removed (Ref. AMM TASK 25-41-41-000-001).
the ceiling panel 221AC is removed as necessary (Ref. AMM TASK 25-23-42-000-001).

(f) For the supply and ventilation ducts in the avionics compartment:

the ACCESS PLATFORM 2M (6 FT) is in position at access door 824 and 811, as necessay.
the access doors 824 and 811 are open (Ref. AMM TASK 52-41-00-010-002).

(g) For the cabin area supply and the cargo-compartment ventilation ducts in the FWD cargo compartment area:

Distribution Ducts Location

the ACCESS PLATFORM 2M (6 FT) is in position at the FWD cargo-compartment door 825,
the FWD cargo-compartment door 825 is open (Ref. AMM TASK 52-30-00-860-001),
the access panels are removed as necessary (Ref. AMM TASK 25-54-12-000-001), (Ref. AMM TASK 25-54-12-000-002) or (Ref. AMM TASK 25-54-12-000-003).

(h) For the cabin area supply ducts in the MID cabin and the wing box area:

the cabin floor panels are removed as necessary (Ref. AMM TASK 53-00-00-000-801).

(i) For the cabin area supply and the cargo-compartment ventilation ducts in the AFT cargo compartment:

the ACCESS PLATFORM 2M (6 FT) is in position at the AFT cargo-compartment door 826,
the AFT cargo-compartment door 826 is open (Ref. AMM TASK 52-30-00-860-001),
the access panels are removed as necessary (Ref. AMM TASK 25-55-11-000-001), (Ref. AMM TASK 25-55-11-000-002), (Ref. AMM TASK 25-55-11-000-003), (Ref. AMM TASK 25-55-12-000-001), (Ref. AMM TASK 25-55-12-000-002) or (Ref. AMM TASK 25-55-12-000-003).

(j) For the riser ducts in the cabin area:

the upper and the lower sidewall panels are removed as necessary (Ref. AMM TASK 25-23-44-000-001) and (Ref. AMM TASK 25-23-43-000-001).

Subtask 21-20-00-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	AIR COND/RECIRC FAN/R/SPLY	3HG	W18
122VU	AIR COND/RECIRC FAN/L/SPLY	1HG	X18

4. Procedure
Subtask 21-20-00-560-050-A

A. Preparation of the Replacement Air-Conditioning Distribution Duct
(1) Where applicable remove the attached components, for example drain hose, blanking caps, restrictors etc. from the removed duct.

NOTE: Identify the respective positions of the restrictors on the removed duct.
The restrictors must be installed in the identical positions on the replacement duct.
The position of the restrictors is not usually interchangeable.

(2) Install the removed components in their correct respective positions on the replacement duct.

Subtask 21-20-00-420-050-A

B. Installation of an Air-Conditioning Distribution Duct
(1) Remove the protective covers from the ends of the ducts and the related connections.
(2) Where applicable make sure that:

Examples of Distribution Duct Connections

(a) The blanking caps (7) and the clamps (2) are correctly installed.
(b) The restrictors (9) are correctly installed in the duct (1).

NOTE: The restrictors (9) must be installed in the original position in the duct.
The position of the restrictors is not usually interchangeable.

Examples of Distribution Duct Attachment Methods

(3) Put the duct (1) in position and, applicable upon duct attachment method:
(a) Install the washers (21) and the screws (20) or,
(b) Put the clamps (25) in position and install the washers (21) and the screws (20) or,
(c) Put the clamps (22) in position on the brackets (23),

make sure that the clamps (22) are correctly installed on the brackets (23),
tighten the clamps (22).

NOTE: On oval shaped ducts make sure that the clamp lock is in the correct position on the duct ellipse.
On the cabin riser ducts make sure that, where possible, the clamp lock is positioned on the outboard side of the duct. This will help to give sufficient clearance when you install the sidewall panels.

(4) Applicable upon the type of duct connection,

Examples of Distribution Duct Connections

NOTE: On oval shaped ducts make sure that the clamp lock is in the correct position on the duct ellipse.
On duct end connections with one coloured marking on only one duct end you must make sure that the ends of the bellows, sleeve or hose cover the coloured marking.
On duct end connections with one coloured marking on each duct end you must make sure that the ends of the bellows, sleeve or hose are between the coloured markings.
On the cabin riser ducts make sure that, where possible, the clamp lock is positioned on the outboard side of the duct. This will help to give sufficient clearance when you install the sidewall panels.

(a) Put the hose (10) and the clamp (2) in position on the duct (1) and tighten the clamp (2) or,
(b) Put the seal (5) in position between the ducts (1) and install the screws (6) and the nuts (4).
(c) Put the bellows (3) and the clamps (2) in position on the duct (1) and tighten the clamps (2) or,
(d) Put the sleeve (8) and the clamps (2) in position on the duct (1) and tighten the clamps (2).
(5) If previously installed:
(a) Apply rub coat on the duct as protection:

cut a piece of the tape Adhesive Film Tape-- Film PTFE - (Material No.05RAJ9) and put it in position on the duct.
wind 2 layers of tape Adhesive Tape-Insulation Blanket - - (Material No.05TGA1) around the duct.

Subtask 21-20-00-865-052-A

C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	AIR COND/RECIRC FAN/R/SPLY	3HG	W18
122VU	AIR COND/RECIRC FAN/L/SPLY	1HG	X18

Subtask 21-20-00-710-050-A

D. Leak Check of the Air-Conditioning Distribution Ducts
(1) Do the pre-conditioning through the LP ground connection (Ref. AMM TASK 12-33-21-618-001).
(2) Do a check for leaks at the duct connections.

NOTE: Leaks are not allowed.

(3) Stop the pre-conditioning through the LP ground connection (Ref. AMM TASK 12-33-21-618-001).

5. Close-up
Subtask 21-20-00-410-050-A

A. Close Access
(1) For the cockpit area supply and ventilation ducts:
(a) Install the access panels as necessary (Ref. AMM TASK 25-13-41-400-001).
(2) For the cockpit riser duct on the LH side at FR13:
(a) Install the ceiling panel 221AC as necessary (Ref. AMM TASK 25-23-42-400-001).
(b) Install the lavatory (Ref. AMM TASK 25-41-41-400-001).
(3) For the supply and ventilation ducts in the avionics compartment:
(a) Install the access panels as necessary (Ref. AMM TASK 53-12-13-400-001).
(b) Close the access doors 824 811 (Ref. AMM TASK 52-41-00-410-002).
(c) Remove the ACCESS PLATFORM 2M (6 FT).
(4) Make sure that the work area is clean and clear of tools and other items.
(5) For the cabin area supply and the cargo-compartment ventilation ducts in the FWD cargo compartment area:

Distribution Ducts Location

(a) Install the access panels as necessary (Ref. AMM TASK 25-54-12-400-001), (Ref. AMM TASK 25-54-12-400-002) or (Ref. AMM TASK 25-54-12-400-003).
(b) Close the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-002).
(c) Remove the ACCESS PLATFORM 2M (6 FT).
(6) For the cabin area supply ducts in the MID cabin and the wing box area:
(a) Install the cabin floor panels as necessary (Ref. AMM TASK 53-00-00-400-801).
(7) For the riser ducts in the cabin area:
(a) Install the upper and the lower sidewall panels as necessary (Ref. AMM TASK 25-23-43-400-001) and (Ref. AMM TASK 25-23-44-400-001).
(8) For the cabin area supply and the cargo-compartment ventilation ducts in the AFT cargo compartment area:
(a) Install the access panels as necessary (Ref. AMM TASK 25-55-11-400-001), (Ref. AMM TASK 25-55-11-400-002), (Ref. AMM TASK 25-55-11-400-003), (Ref. AMM TASK 25-55-12-400-001), (Ref. AMM TASK 25-55-12-400-002) or (Ref. AMM TASK 25-55-12-400-003).
(b) Close the AFT cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-002).
(c) Remove the ACCESS PLATFORM 2M (6 FT).
(9) Remove the WARNING NOTICE(S).

Subtask 21-20-00-862-050-A

B. De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002)

[Rev.10 from 2021] 2026.04.01 04:54:39 UTC